Coefficient of a32 in the binomial expansion of (a4−1a3)15 is:
15C4
-15C4
0
None
Tr+1 = 15Cr(a4)15−r(−1a3)r
Equating power of a to 32
60-7r = 32 then r = 4
Prove that the coefficient of xn in the binomial expansion of (1+x)2n is twice the coefficient of xn in the binomial expansion of (1+x)2n−1.
The value of 1.C1+3.C3+5.C5+7.C7+.... whereC0,C1,C2.....Cn are binomial coefficients in the expansion of (1+x)n is: